A woman in London has become the first to give birth after having her fertility restored using ovarian tissue frozen before the onset of puberty, doctors said Wednesday.

Moaza Al Matrooshi, 24, had her right ovary removed when she was nine years old before undergoing for a severe blood disorder, according to the University of Leeds where the was frozen.

Her fertility was restored after the preserved tissue was transplanted last year, the university said.

"It is the first time that the success of the procedure has been shown in a pre-pubertal girl, and I'm delighted that this has had her baby," said Helen Picton, head of the university's reproduction and early development division, who carried out the freezing.

The young woman gave birth to a baby boy at the private Portland Hospital in London on Tuesday, according to the BBC.

"It's like a miracle. We've been waiting so long for this result—a healthy baby," she told the British broadcaster.

The Dubai national was born with beta thalassaemia, a blood disorder that reduces the production of haemoglobin and can be life-threatening.

She needed chemotherapy in preparation for a to treat the disorder but the treatment damaged her remaining ovary, bringing on the menopause in her early twenties, Leeds university said.

"Following her transplant her hormone levels began returning to normal, she began ovulating and her fertility was restored," the university explained on its website.

"Moaza is a pioneer and was one of the first patients we helped back in 2001, before any baby had been born from ovary tissue preservation," said Picton.

Last year, a Belgian woman gave birth after undergoing the same procedure with ovarian tissue frozen when she was 13 years old.

However, "unlike Moaza, she had begun going through puberty when her ovary was removed," according to the university.

Adam Balen, chairman of the British Fertility Society, said: "This is a ground-breaking step in this area of and has the potential to help many young people who face cancer treatment preserve their fertility chances in the future."